Electromagnetic relay with a narrow construction and a method of manufacture thereof

ABSTRACT

The relay has, one after the other on an elongate, narrow base body, a magnetic system and a contact arrangement having at least one fixed contact carrier and at least one movable contact spring. The contact carriers are in this case each embedded by a middle section into the plastic of a base body in such a way that their connecting lugs lie in a plane parallel to the longitudinal axis of the relay, while their contact-making end sections, which emerge on the upper side of the base body, lie in planes which are parallel to one another and perpendicular to the plane of the connecting lugs. This enables dimensionally accurate embedding of the contact carriers with good insulation with respect to the magnetic system and with easy processing from a sheet-metal plate.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to electromagnetic relays and,more specifically, electromagnetic relays having a narrow, elongatedbase body with fixed contact carriers embedded in the base body that arecut from a common plate of sheet metal. The present invention alsorelates to a method of manufacturing such a relay.

Relays having a narrow structure of this type are disclosed for examplein DE 38 29 035 C2 and DE 38 35 105 C2. The anchoring of the contactcarriers in a single row and the position of the connecting lugs in asingle sheet-metal plane result in advantageous production because thepartially cut-free contact carrier elements which are still connected tothe plate enable easy handling in the production run and accuratepositioning in the base body. In the case of the known relay structure,the contact-making sections of the contact carriers are arrangedtogether with an armature underneath a coil winding with a toroidal ironcore, the actuation direction being effected transversely with respectto the longitudinal axis of the relay structure. Insulation between themagnetic system and load circuit is problematic, however, due to theinterlacing of armature and contact springs. High currents cannot beswitched by this system on account of the excessively small insulatingclearances. In addition, a changeover contact can be realized only withdifficulty in the case of this structure; at least such a changeovercontact would manifest itself at the expense of the narrow structure,given said actuation direction.

DE 34 14 731 A1 has also already disclosed a basic structure of a relayin which a magnetic system and a contact arrangement are arranged oneafter the other in the longitudinal direction of the relay, the contactarrangement being actuated by means of a slide which can be movedparallel to the longitudinal axis of the relay. However, a narrowstructure is not intended in that case, since two sets of contacts arearranged next to one another transversely with respect to thelongitudinal axis of the relay. Although the contact carriers areembedded in the base body of the relay, the flat connecting lugs eachlie in planes transversely with respect to the longitudinal axis of therelay, with the result that processing-from a plate is in that caseneither striven for nor would it actually be implementable.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a JIG, narrowelectromagnetic relay of the type mentioned in the introduction and tospecify a method for its production which, given any desired contactcomplement as make contact, break contact and, in particular, aschangeover contact, always enables the same narrow structure, at thesame time permits large insulating clearances with respect to themagnetic system and enables particularly simple production byarrangement of the connecting lugs in a single sheet-metal plane; inthis case, the intention is to enable the connecting lugs to be embeddedin the base body whilst hanging at least partially from a plate.

In the case of a relay of the abovementioned type, this aim is achievedaccording to the invention by virtue of the fact that all of the contactelements are each angled by their middle section in the region ofanchoring in the base body, in such a way that their contact-making endsections, from their point of emergence from the base body onwards, arelocated in a single row, but in planes which are parallel to one anotherand perpendicular to the base plane and to the plane of the connectinglugs, and that each contact spring is actuated in the direction of thelongitudinal axis of the relay.

In the case of the relay according to the invention, then, thecontact-making sections of the contact carriers are located transverselywith respect to the longitudinal axis of the relay, thereby enablingactuation in the direction of this longitudinal axis. Since the contactcarriers are always arranged only in one row, a narrow structure of therelay is always ensured since the width is determined by the dimensionof the magnetic system and even a changeover contact does not increasethe width. It would even be possible for two sets of contacts to bearranged one after the other in the longitudinal direction of the relayand be actuated by a longitudinal slide. In contrast to the known relayswith such an arrangement of the contact carriers and such an actuationdirection, however, in this case the connecting lugs of the contactcarriers do not extend parallel to the contact-making sections thereof;rather the common plane of the connecting lugs is located perpendicularto the planes of the contact-making sections. In this way, not only isthe requirement for a connection configuration in one plane (inlineconfiguration) taken into account, but also the processing of thecontact carriers from a plate in the production run is made possible.The transition from the connection plane of the contact carriers to therespective planes of the contact-making end sections is made in theanchoring region within the base body. The parts projecting from thebase body are thus aligned in their respective plane and are no longerbent; as a result, due to the anchoring in the base body, they can bebrought with high accuracy into their end position and be fixed in thisend position.

The contact carriers are expediently angled in their middle section,which is anchored in the base body, in each case at least about twobending axes which are perpendicular to one another, as a result ofwhich the transition from the plane of the connecting lugs to therespective contact plane is effected, yet at the same time it becomespossible to obtain the contact carriers from the plate in a manner thatsaves a great deal of material. As a result of the angling in the regionof the base body, it is possible for the connecting lugs to have adesired, large insulation clearance with respect to one another, whiletheir contact-making end sections acquire the short contact separationthat is necessary.

In an advantageous embodiment, it is provided that, for a changeovercontact, two fixed contact carriers are embedded in the material of thebase body, while a spring carrier lying between them is inserted by acontact spring, fastened to said spring carrier, into a laterally openslot in the base body. However, it would also be possible partially tocut free the spring carrier together with the fixed contact carriersfrom the common plate, then to provide it with the contact spring and,whilst still connected to the common plate, to embed it with the fixedcontact carriers jointly into the material of the base body. Inaddition, it would alternatively be conceivable to obtain both thecontact spring and the fixed contact carriers from the same material ofa common plate and embed them jointly in the base body.

The inventive configuration of the contact arrangement can be realizedin a particularly advantageous manner in the case of a relay in whichthe base body has a partition between the magnetic system and thecontact arrangement as well as an insulating wall on a long side of thebase body, which insulating wall is perpendicular with respect to thebottom side; in this case, particularly favorable insulation between thecontact carriers and the magnetic system is produced when the plane ofthe connecting lugs runs on one side in the region underneath thelongitudinal insulating wall.

In a method for the production of the relay according to the invention,first of all a base body is molded from plastic and provided with thecontact carriers, an electromagnetic system then being mounted on thisbase body; in this context, according to the invention, at least onecontact carrier having a connecting lug, a middle section and acontact-making end section is cut free from a sheet-metal plate in sucha way that it still hangs from the plate by its respective connectinglug; afterwards, the middle section of each contact carrier is bent outof the plane of the plate in such a way that the contact-making endsection is located in its own plane which is perpendicular to the baseplane and to the plane of the plate; and the base body is then molded byembedding the respective middle sections in plastic, after which finallythe connecting lugs are separated from the sheet-metal plate.

Depending on the desired structure of the contact arrangement, it ispossible to obtain only the fixed contact carrier or carriers from theplate and embed it or them into the base body, while a spring carrierwith the contact spring fastened thereto is subsequently inserted into aslot in the base body, or else to cut free the spring carrier togetherwith the fixed contact carriers and jointly embed them. Other objectsand advantages of the present invention will become apparent fromreading the following detailed description and appended claims, and uponreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in more detail below using an exemplaryembodiment with reference to the drawing.

In the drawing:

FIG. 1 illustrates two successive sections of a sheet-metal plate in theproduction run with a pair of fixed contact carriers in two successiveprocessing stages,

FIG. 2 illustrates the sheet-metal plate section of FIG. 1 in aperspective view,

FIG. 3 illustrates the sheet-metal plate section of FIG. 2 in a furtherproduction stage,

FIG. 4 illustrates a relay base body, obtained by encapsulating asheet-metal plate section by injection molding, with a contact springthat can additionally be inserted,

FIG. 5 illustrates a finished relay system mounted on the base body ofFIG. 4 (without a housing cap).

It should be understood that the drawings are not necessarily to scaleand that the embodiments are sometimes illustrated by graphic symbols,phantom lines, diagrammatic representations and fragmentary views. Incertain instances, details which are not necessary for an understandingof the present invention or which render other details difficult toperceive may have been omitted. It should be understood, of course, thatthe invention is not necessarily limited to the particular embodimentsillustrated herein.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

FIGS. 1 to 4 show the different method steps for obtaining a relay basebody with contact arrangement by partly encapsulating a sheet-metalplate by injection molding. In this case, two fixed contact carriers 2and 3 are obtained from a plate 1 and processed successively in theproduction cycle. Thus, FIGS. 1 and 2 show these fixed contact carriersin a first method stage I and in a second method stage II.

In the first method stage I, the fixed contact carriers 2 and 3 are eachcut free from the plate. They each have a connecting lug 21 and 31,respectively, a middle section 22 and 32, respectively, for embedding inthe yet to be described base body, and a contact-making end section 23and 33, respectively, which is already provided with a fixed contact 24and 34, respectively, in this stage. The method stage II is reached bybending the middle section 22 and 32 about mutually perpendicularbending lines 25, 26 and 27 and, respectively, 35 and 36, in whichmethod stage II the two contact-making end sections 23 and 33 arelocated opposite one another with their fixed contacts 24 and 34parallel.

FIG. 3 shows a further method sequence. This firstly shows the stage IIas in FIG. 2 once again, said stage being followed by the stage III. Inthis stage, a plastic base body 4 of the relay is formed byencapsulating the middle sections 22 and 32 by injection molding, whichbase body, on the one hand, is connected to the plate 1 via theconnecting lugs 21 and 31 (visible in FIG. 4), while, on the other hand,the end sections 23 and 33 of the fixed contact carriers protrude fromthe plastic of the base body. The angular portions of the fixed contactcarriers are thus completely embedded in the plastic. All that arevisible are the connecting lugs 21 and 31 lying in the plane of theplate 1, on the one hand, and the contact-making end sections 23 and 33lying in planes which are perpendicular thereto. As a result, the fixedcontacts can be positioned very exactly with regard to the base body.Subsequent deforming of the contact carriers is not necessary. Inaddition, this extensive embedding results in large insulatingclearances with respect to the magnetic system of the relay which, inaccordance with FIG. 5, is arranged on that end of the base body whichis opposite to the fixed contact carriers. In the region where the fixedcontact carriers 2 and 3 are encapsulated by injection molding, the basebody 4 forms a contact block 41, which, with ribs and grooves, formslarge insulating clearances with respect to the magnetic system. Inorder to accommodate the magnetic system, the base body 4 forms abaseplate 42, the underside of which defines a base plane 11. Asinsulation between the magnetic system and the contact arrangement, thebase body has, located perpendicularly to the baseplate, an insulatingwall 43 as well as a longitudinal wall 44 on a long side, whichlongitudinal wall forms, together with a top wall 45, a half-shell foraccommodating one end of the yet to be described magnetic system.

As can be seen in FIG. 4, with a view of the base body from an oppositeside, an accommodating slot 5 for securing an inserted contact spring 6is provided in this case between the two fixed contact carriers 2 and 3.The contact spring itself is fixed on a spring carrier 62 with aconnecting lug 61, for example by spot welding. The spring carrier 62 isangled about a bending axis 65 with respect to its connecting lug 61; inaddition, the contact spring 6 is angled upward about a bending axis 66which is perpendicular thereto. Consequently, in the case of the contactspring arrangement, too, the spring section 63 carrying a contact 64lies in a plane perpendicular to the plane of the connecting lug 61.After the connecting lugs 21 and 31 have been separated at the dashedlines 28 and 38 and after the contact spring arrangement 6 has beeninserted into the slot 5, the connecting lug 61 lies in a plane with theconnecting lugs 21 and 31, while the contact-making section 63 of thecontact spring 6 lies parallel between the two contact-making endsections 23 and 33 of the fixed contact carriers.

As has already been mentioned beforehand, it would also be possible tocut free the spring carrier 62 with the fixed contact carriers 2 and 3from the plate 1, in which case the resolution of the individualsections would have to be effected in a somewhat different manner fromthat according to FIG. 1. The contact spring 6 could then be fitted tothe cut-free spring carrier 62 and be encapsulated by injection moldingtogether with the latter and the fixed contact carriers during theformation of the base body. If it is possible to use one and the samespring sheet-metal material both for the contact spring and for thefixed contact carriers, all these parts could be jointly cut free andencapsulated by injection molding.

FIG. 5 shows the finished mounted relay. Here, in the base bodyaccording to FIG. 4, after the contact spring 6 has been inserted, amagnetic system 7 having a coil 71, a core-yoke arrangement 72 and anarmature 73 is placed onto the baseplate 42 and pushed from a long sideinto the half-shell formed by the walls 43, 44 and 45. Since the wall 44covers the magnetic system toward one side in the direction of thecontact system, the connecting lugs 21, 31 and 61 essentially lie belowthis longitudinal wall 44. In this way, the creepage paths from theconnecting lugs to the open side of the half-shell and thus to themagnetic system are additionally lengthened.

A slide 8 transmits the switching movement of the armature 73 to the endsection 67 of the contact spring 6, as a result of which thesemicircularly cut-free contact-making section 63 of the spring isactuated.

From the above description, it is apparent that the objects of thepresent invention have been achieved. While only certain embodimentshave been set forth, alternative embodiments and various modificationswill be apparent from the above description to those skilled in the art.These and other alternatives are considered equivalents and within thespirit and scope of the present invention.

What is claimed is:
 1. An electromagnetic relay comprising:a narrowelongated base body fabricated from an insulating material andcomprising an underside and an upper side, the underside defining a baseplane, the upper side accommodating an electromagnetic system and acontact arrangement, the base body further comprising a longitudinalaxis, the contact arrangement comprising at least one fixed contactcarrier and at least one movable contact spring, the fixed contactcarrier comprising a middle section disposed between a flat connectinglug and a contact-making end section, the movable contact spring alsocomprising a middle section disposed between a flat connecting lug and acontact-making end section, the flat connecting lugs of the fixedcontact carrier and movable contact spring each having a width and athickness, the width of each flat connecting lug being disposed in acommon plane parallel to the longitudinal axis of the base body andperpendicular to the base plane, the middle section of the fixed contactcarrier being embedded in the material of the base body and anchoringthe fixed contact carrier to the base body, the contact-making endsections of the fixed contact carrier and the movable contact springbeing disposed in alignment with one another and perpendicular to thebase plane and to the common plane of the connecting lugs, thecontact-making end section of the contact spring being actuated in adirection parallel to the longitudinal axis of the base body.
 2. Therelay of claim 1, wherein the middle section of the movable contactspring engages the base body and anchors the movable contact spring tothe base body.
 3. The relay of claim 1 wherein the connecting lug of themovable contact spring engages the base body and anchors the movablecontact spring to the base body.
 4. The relay of claim 1, wherein eachfixed contact carrier further comprises a first bend positioned along afirst bending axis disposed between the connecting lug and the middlesection and a second bend positioned along a second bending axisdisposed between the contact-making end section and the middle section,the first and second bending axes being perpendicular to one another. 5.The relay of claim 1 wherein the at least one fixed contact carriercomprises two fixed contact carriers, both of which are embedded in thematerial of the base body, andthe movable contact spring is connected toa spring carrier disposed between the fixed contact carriers, and thebase body comprises a lateral slot, the spring carrier beingaccommodated in the lateral slot of the base body.
 6. The relay of claim1 wherein the base body comprises a partition disposed between themagnetic system and the contact arrangement.
 7. An electromagnetic relaycomprising:a narrow elongated base body fabricated from an insulatingmaterial and comprising an underside and an upper side, the undersidedefining a base plane, the upper side accommodating an electromagneticsystem and a contact arrangement, the base body further comprising alongitudinal axis, the contact arrangement comprising at least one fixedcontact carrier and at least one movable contact spring, the fixedcontact carrier comprising a middle section disposed between aconnecting lug and a contact-making end section, the movable contactspring also comprising a middle section disposed between a connectinglug and a contact-making end section, the connecting lugs of the fixedcontact carrier and movable contact spring being disposed in a commonplane parallel to the longitudinal axis of the base body andperpendicular to the base plane, the middle section of the fixed contactcarrier being embedded in the material of the base body and anchoringthe fixed contact carrier to the base body, the contact-making endsections of the fixed contact carrier and the movable contact springbeing disposed in alignment with one another and perpendicular to thebase plane and to the common plane of the connecting lugs, thecontact-making end section of the contact spring being actuated in adirection parallel to the longitudinal axis of the base body, whereinthe base body comprises a partition disposed between the magnetic systemand the contact arrangement, and wherein the base body further comprisesan insulating wall extending longitudinally along one side of the basebody, the insulating wall being disposed perpendicular to the baseplane, the insulating wall being coplanar with the connecting lugs anddisposed above the connecting lugs.
 8. An electromagnetic relaycomprising:a narrow, elongate base body fabricated from an insulatingmaterial and comprising an underside and an upper side, the undersidedefining a base plane, the upper side accommodating an electromagneticsystem and a contact arrangement, the base body further comprising alongitudinal axis, the contact arrangement comprising at least two fixedcontact carriers and at least one movable contact spring, the fixedcontact carriers each comprising a middle section disposed between aflat connecting lug and a contact-making end section, the movablecontact spring also comprising a middle section disposed between a flatconnecting lug and a contact-making end section, the contact-making endsection of the movable contact spring being disposed between thecontact-making end section of the fixed contact carriers, the flatconnecting lugs of the fixed contact carriers and movable contact springeach having a width and a thickness the width of each flat connectinglug being disposed in a common plane parallel to the longitudinal axisof the base body and perpendicular to the base plane, the middlesections of the fixed contact carriers being embedded in the material ofthe base body and anchoring the fixed contact carriers to the base body,the contact-making end sections of the fixed contact carriers and themovable contact spring being disposed in alignment with one another andperpendicular to the base plane and to the common plane of theconnecting lugs, the contact-making end section of the contact springbeing actuated between the contact-making end sections of the fixedcontact carriers and in a direction parallel to the longitudinal axis ofthe base body.
 9. The relay of claim 8, wherein the middle section ofthe movable contact spring engages the base body and anchors the movablecontact spring to the base body.
 10. The relay of claim 8 wherein theflat connecting lug of the movable contact spring engages the base bodyand anchors the movable contact spring to the base body.
 11. The relayof claim 8, wherein each fixed contact carrier further comprises a firstbend positioned along a first bending axis disposed between theconnecting lug and the middle section and a second bend positioned alonga second bending axis disposed between the contact-making end sectionand the middle section, the first and second bending axes beingperpendicular to one another.
 12. The relay of claim 8, wherein themovable contact spring is connected to a spring carrier disposed betweenthe fixed contact carriers, andthe base body comprises a lateral slot,the spring carrier being accommodated in the laterally slot of the basebody.
 13. The relay of claim 7, wherein the base body comprises apartition disposed between the magnetic system and the contactarrangement.
 14. The relay of claim 13, wherein the base body furthercomprises an insulating wall extending longitudinally along one side ofthe base body, the insulating wall being disposed perpendicular to thebase plane, the insulating wall being coplanar with the connecting lugsand disposed above the connecting lugs.
 15. A method of manufacturing arelay comprising the following steps:cutting at least one fixed contactcarrier comprising a connecting lug and a contact-making end sectionwith a middle section disposed there between from a sheet-metal platedisposed in a plane while maintaining a connection between theconnecting lug and an elongated remaining portion of the plate, themiddle section being bent out of the plane of the plate in such a waythat the contact-making end section is disposed perpendicular to theplane of the plate, molding a base body from insulating material andembedding the middle section of the contact carrier in the insulatingmaterial with the remaining portion of the plate extending along alongitudinal axis of the base body and below a base plane of the basebody, the base body being narrow and elongated comprising an undersideand an upper side, the underside defining the base plane, the remainingportion of the plate and the terminal lug extending perpendicularlydownward from the base plane, separating the connecting lugs from theremaining portion of the plate and mounting an electromagnetic system onthe upper side of the base body.
 16. The method of claim 15, wherein thestep of connecting a contact spring further comprises embedding themiddle section of the contact spring in the base body.
 17. The method ofclaim 15, wherein the contact spring is also cut from the sheet metalplate.
 18. The method of claim 15, wherein each fixed contact carrierfurther comprises a first bend positioned along a first bending axisdisposed between the connecting lug and the middle section and a secondbend positioned along a second bending axis disposed between thecontact-making end section and the middle section, the first and sectionbending axes being perpendicular to one another.
 19. The method of claim15, wherein the at least one fixed contact carrier comprises two fixedcontact carriers, both of which are cut from the sheet-metal plate in aspaced apart fashion and both of which are embedded in the base body ina spaced apart fashion,the method further comprising the stepofconnecting a contact spring to the base body between the two fixedcontact carriers, the contact spring also comprising a connecting lugand a contact-making end section with a middle section disposed therebetween, the connecting lug of the contact spring being coplanar withthe connecting lugs of the fixed contact carriers and the contact-makingend section of the contact spring being parallel to the contact-makingend sections of the fixed contact carriers.
 20. The method of claim 19,wherein the contact spring comprises a spring carrier cut from a sheetmetal plate which forms said connecting lug and said middle section ofthe contact spring, the contact-making spring end section beingconnected to the spring carrier,the step of connecting the contactspring to the base comprising inserting the spring carrier into a slotin the base body.
 21. The method of claim 19, wherein the contact springcomprises a spring carrier cut from a sheet metal plate which forms saidconnecting lug and said middle section of the contact spring, thecontact-making spring end section being connected to the springcarrier,the step of connecting the contact spring to the base comprisingembedding the spring carrier in the base body.